Ink jet printers have printheads that operate a plurality of inkjets that eject liquid ink onto an image receiving member. The ink may be stored in reservoirs located within cartridges installed in the printer. Such ink may be phase-change, aqueous, oil, solvent-based, UV curable ink, or an ink emulsion. A typical full width scan inkjet printer uses one or more printheads. Each printhead typically contains an array of individual nozzles for ejecting drops of ink across an open gap to an image receiving member to form an image. The image receiving member may be a continuous web of recording media or a series of media sheets. In some print modes, the array of printheads has a width that exceeds the width of the print medium. For example, some inkjet printers include arrays of printheads with an array of inkjets that span a width of 48 cm in the print zone, while many print media have narrower widths, such as a letter size media sheet that has a width of only 21.6 cm and a length of only have width of only 27.9 cm.
During prolonged printing operations, only a portion of the inkjets in the printheads form printed images on the print media, while other inkjets that are located in regions of the print zone beyond the edges of the print medium remain idle. The liquefied ink in the idle inkjets may dry out due to evaporation through the inkjet nozzle. The dried ink in the inkjets renders the inkjets inoperable. The printer must perform purge operations or other printhead maintenance operations to return the inoperable inkjets to working order prior to performing printing operations on larger media sheets that receive ink from the inoperable inkjets. The maintenance process often consumes both ink and time, which decreases the effective throughput of the printer. Consequently, improvements to inkjet printers to reduce the occurrence of inoperable inkjets during printing operations for print media with a wide range of widths would be beneficial.